Renault have made it known that they want to scale back their engine supply arrangement. They feel that supplying three teams is ideal (though they’re willing to supply four). They obviously won’t give up on Red Bull, and they have an off-track relationship with Caterham. Toro Rosso want Renault engines, and given their relationship with Red Bull, it makes sense for them to use Renault, too. That means Williams and Lotus would have to find new deals. Lotus have been linked to a Honda switch in 2015, so they might keep Renault for an extra season on a one-year deal the way McLaren are sticking with Mercedes.

That would leave Williams as the odd one out. A move to Mercedes makes sense, because the Mercedes engine is probably the best on the grid. Especially in terms of raw power, which would benefit Williams and their flagging fortunes.

Williams need more than Ross Brawn. Ross is a great leader, but to be a great leader, you need a great car. The Renault dream reunion has not gone the way Williams has hoped and with the loss of Mclaren and the uncertainty of SFI, Mercedes would be crazy not to snap Williams up. I’m not so sure Caterham will stay with Renault myself as the have not gained what seems like any advantage from using the Redbull drivetrain and I’m sure it’s not cheap. Does Renault want to scale back engine supply as the might start their own team, again.

That sounds fairly right to me. Clearly the Renault engine isn’t fit for the already weak FW35, so Mercedes power might be a smart move. Also, I’ve heard that Renault’s 2014 engines will be the most expensive on the market, at around 25 mil and as Williams’s financial status isn’t exactly good, the less-expensive (yet still as good, I believe) Mercedes engine could solve that problem. And the, we have to consider that Merc will lose a team as of 2015 (when McLaren switches to Honda) and supplying Williams might be the key to keep the a certain equilibrium.
So, there you go…a lot of reasons why this could (and should) happen.

Seems like there could be a big change around next year.
WARNING MASSIVE RUMOUR BELOW

Ferrari
McLaren-Honda (new rumour suggests that Honda could return next year rather than 2015)
Mercedes
Lotus-Renualt
Red Bull-Renault
Williams – Mercedes
Force India (uncertain if they will even stick around for next year let alone its engine)
Marrusia-Ferrari (they will almost certainly use Ferrari engines for next year)
Sauber – Ferrari
Caterham (unknown, maybe renualt)
Torro Rosso – Renault (an anncoucement is being made soon about the switch)

Clearly the Renault engine isn’t fit for the already weak FW35, so Mercedes power might be a smart move

It’s a lot easier to suggest forthcoming changes for teams who’s current form isn’t great – it seems that Williams may be, just perhaps, starting to understand what’s going on with the FW35 (see Monaco Thursday practice 1).

Their problems are aero-based rather than with the engine. Plus they’ve only been with Renault power since the start of last year, so it’s a little early to jump to conclusions in my opinion. Plus, it’s perhaps a little late to be making that sort of switch, surely? I’m guessing there’ll already be a lot of correspondence with their engine suppliers now work on the 2014 cars has begun, with such a big change. Of course, I could be wrong.

While Prisoner Monkeys has a good point in saying Renault is likely to be Caterham’s first pick because of their off-track work, I have seen their name mentioned in the engine rumors. It would seem they aren’t too happy about Renault’s engine prices, and are considering Ferrari or Mercedes power as well. Dutch sites are claiming the following;

Mind you, they have people on the paddock. I’ve seen some blogs speculate Ferrari is going to supply half the field next season, but I don’t think Ferrari will expand beyond 3 teams.

I’d like a good engine shake-up to be honest. And silly season for suppliers can be really fun in hindsight too, I remember rumors Prost was getting Mercedes engines and McLaren switching back to Peugeot back in 2000..

Renault wanting to lose a deal with somebody, and Toro Rosso wanting to pick up a Renault engine, combined with their relationship with Red Bull would suggest that both Williams and Lotus will need new engines. I don’t know what the current contracts are, or how long they last, but I’d expect something like:

Williams to switch to Mercedes, given the rumours, I guess it would make sense, especially with McLaren no longer using their engines. I’ve heard (I think from Autosport) that Honda won’t supply anyone else in 2015, so that could mean that Lotus will have to wait for 2016, if they want Honda. Sauber are likely to keep with Ferrari, with Marussia making the switch as well.

So, for me the question is what Lotus will do, if they do part with Renault. Ferrari or Mercedes for the next couple of years?

I don’t see Lotus ditching Renault, I expect Renault to still supply 3 teams being RBR, STR and Lotus. That makes investing in development worth while. Mercedes I believe will follow suit with 3 teams, themselves, SFI and Williams. Honda will be looking to supply more teams but the fact that they are no coming on board until 2015 makes it hard for teams to commit especially as they are yet to be proven.